Monday, April 27, 2009

Simulation and non-local realism

Realism is the viewpoint according to which an external reality exists independent of observation. According to Bell’s theorem any theory that is based on the joint assumption of realism and locality (meaning that local events cannot be affected by actions in space-like separated regions – something that Einstein would not swallow) clash with many quantum predictions. In such cases, “spooky action at a distance” is necessarily assumed in order to explain phenomena such as quantum entanglement. This is called non-local realism. A recent paper by Simon Groblacher et al (An experimental test of non-local realism, Nature, Vol. 446, 19th April 2007, pp. 871-5) showed that giving up the concept of non-locality is not sufficient to be consistent with quantum experiments, unless certain intuitive features of realism are also abandoned. Let us see how these results may correspond to assumptions made into our simulation-based New Narrative.I would like to take an example from cosmology, indeed the very simulation of the standard cosmological model. The logic of the simulation goes like this. Assumption 1: The universe maps unto an external reality which, somehow (i.e. via known, or unknown-as-yet, natural laws) maps also unto our coupled media of detection instruments plus consciousness. This may be called “the perceived universe”. It usually depicts an image of the cosmos, galaxies and gas clusters spreading in all directions and in all magnificence. A mathematical model is then developed based on the prevailing cosmological theory that aims to explain the “perceived universe”. This model runs on a computer, which is the external reality substrate of the simulation. In other words, there is, or so we assume, a “reality” of hardware that runs our simulation (assumption 2). The result of the simulation is also an image of the cosmos. Comparing the two images we refine the model further until the two images appear identical. When we achieve an identical pair of images then we conclude that our mathematical model has been a successful one, i.e. a valid description of external reality.It is obvious that our conclusion may be potentially flawed, on the basis of our two main assumptions. Furthermore, our assumptions call upon the quantum nature of the cosmos which, as the aforementioned paper has demonstrated, seems to reject non-local realism. Thus, we are left with a revision of assumptions about realism.Which happen to be inherent in the New Narrative, the most poignant revision of reality being the decoherence of Selfhood.By deconstructing the Self, by rejecting the narcissism of psychoanalysis, by re-introducing a mystical layer of dualism in the nature of consciousness, we arrive at a counterfactual definiteness and in a world not completely deterministic. The result may be a chorus of out-of-tune artwork but it is also a result closer to what our best validated experiments show. If “external reality” is a wonderland of curious objects and events then our revised “inner reality” of the New Narrative is an equally exotic place. But should we take such a phantasmagoric correspondence as a sign of progress? Should we convince ourselves that we have, at last, by entering our self-simulated world, arrived serendipitously at the Holy Grail of “reality”? Ironically perhaps, the very dynamics of decoherence prevent us from answering such questions. When determinism is thrown out of the window, then all one can do is lean onto the ledge and peer outside, in wander and astonishment, to the changing view of a perplexing world beyond our wildest imagination. And that is exactly what the New Narrative tries, and forever fails, to describe.